According to the study funded by the National Institute of Environmental Health Sciences (NIEHS), blood lead concentrations measured in more than 1,300 preschool children in China were associated with increased risk of behavioral and emotional problems, such as being anxious, depressed, or aggressive, while the average blood lead level in the children was 6.4 micrograms per deciliter.
NIEHS Health Scientist Administrator Kimberly Gray said that the research focused on lower blood lead levels than most other studies and adds more evidence that there is no safe lead level and it is important to continue to study lead exposure in children around the world, and to fully understand short-term and long-term behavioral changes across developmental milestones. It is well-documented that lead exposure lowers the IQ of children.
In the United States, lead exposure usually comes from lead-containing products, such as paint, caulking, and pipe solder, in older homes, while in China, lead exposure is more often related to air pollution.
U.S. studies have reported that lead exposure causes externalizing behavior problems, such as aggressiveness and bullying, which may lead to truancy and even jail time as children get older. In this study, children with higher blood lead levels had internalizing problems, such as anxiety and depression, as well as some externalizing problems.
The study was published online in the journal JAMA Pediatrics.